Atlantic Bay Scallop (fragment)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Argopecten, Species: Argopecten irradians · Pectinidae (Scallop family) · Bivalve (two-shelled), specifically a shell fragment with a fan/disc shape
Species
Argopecten irradians
Shell Type
Bivalve (two-shelled), specifically a shell fragment with a fan/disc shape
Family
Pectinidae (Scallop family)
Size
Approximately 1 to 1.5 inches for the visible fragment; typical whole adults range from 2 to 3 inches.
Color & Pattern
Displays a weathered grayish-white base with faint hints of purplish-brown radial banding. The colors appear somewhat sun-bleached and worn from wave action.
Rarity
Very Common
Habitat
Shallow marine waters, typically found in seagrass beds, sand, and muddy substrates in bays and estuaries.
Geographic Range
Western Atlantic Ocean, ranging from Nova Scotia down to the Gulf of Mexico, Caribbean, and South America.
Description
This is a fragment of a bivalve shell featuring distinct, prominent radial ribs and fine surface striations characteristic of scallops. The broken edges show the fragile, layered calcite structure common in pectinids.
Key Features
Pronounced radial ribs radiating outward from the umbo, regular symmetrical pleats, and a flattened disc profile typical of swimming scallops.
Collector Value
Minimal collector value due to its fragmented and worn condition. Whole, gem-quality specimens are popular in crafts and casual collections.
Condition Notes
Fair condition; this is a broken fragment rather than a whole valve, exhibiting surface wear and fading typical of beach-tossed specimens. Low collectibility grade due to damage.
Interesting Facts
Scallops are unique among bivalves because they can swim by rapidly clapping their valves together to jet water. They also possess dozens of simple bright blue eyes along the mantle edge.
Ecological Role
Bay scallops are filter feeders that help maintain water clarity and quality in estuarine ecosystems. They serve as an important food source for fish, crabs, and sea birds.
Similar Species
Lion's Paw Scallop (Nodipecten nodosus) and Calico Scallop (Argopecten gibbus), which can be distinguished by rib patterns, knob formations, and coloration.
Beach Finding Tips
Look along sandy and shell-strewn high tide lines in sheltered bays and near seagrass beds, especially after storms.